InThe Five-Year Engagement, Jason Segel and Emily Blunt play a couple navigating the twists of a long, complicated relationship. The two walked the red carpet together at the premiere last night, which kicked off the Tribeca Film Festival, joking with reporters and mugging for photos at the Ziegfeld Theatre. But at the after-party at MoMA, Segel had new love interest Michelle Williams on his arm. The pair held hands and openly socialized with guests like Robert De Niro, Elizabeth Banks,and Julia Louis-Dreyfus—although it seems that they’re still keeping the relationship somewhat out of the public eye, since Williams successfully avoided having her picture taken throughout the evening.

One thing to which Segel was fully, publicly committed were his nude scenes in the movie. “He does like to be naked,” producer Rodney Rothman told Vanity Fair. “We filmed him naked for this movie, and it was not in the script, and nobody suggested it. It was Jason that suggested it. Like, ‘Do you think the scene would be better if I was naked in it?’” The full-frontal shot didn’t make it into the movie. “The scene was better without it. It was there, and it was totally Jason’s idea,” Rothman said.

Segel confirmed that the nudity was his idea when we caught up with him later. “I thought of it at the time, and I thought of it, maybe, as an homage to ForgettingSarah Marshall,” he told us. “But then when we saw it, it just seemed gratuitous.”

Segel’s longtime collaborator Judd Apatow has a simple explanation for the How I Met Your Motherstar’s propensity for getting naked on film. “You know, when you’re built like Jason you’re always looking to do some full-frontal,” Apatow said with a shrug. “And at some point, I’ve had enough.” Segel agreed. “There’s no need for it at this point. I’ve had it on the screen before; people know what it looks like. Enough is enough,” he told us. “And we also couldn’t find a lens wide enough.”

Later at the party, which was done up in a wedding theme, complete with white-and-pink beribboned cakes and signs on the buffet tables reading, “The Wedding Dinner,” we ran into Bill Hader, who imagined what his S.N.L. character Stefon’s wedding would entail. “He would have throw-up music,” Hader said. “I think he would have one of those weddings where you’d be moving to a lot of different locations,” he said, laughing, clearly getting into the scenario. “And food wise, I think it would be all liquid stuff. I don’t think he would have much, like, solid foods there.” So is Stefon on a liquid diet? “He doesn’t want to have to think; he doesn’t want to worry about it. He doesn’t want to worry about seating stuff. He doesn’t want to do any of those things,” Hader said. “Plus, he’ll forget that he got married. You know, the next morning they’ll have to remind him.